In the manufacture of an electronic device, a plasma processing apparatus is used. The plasma processing apparatus is generally equipped with a chamber main body, a stage and a radio frequency power supply. An internal space of the chamber main body is configured as a chamber. The chamber main body is grounded. The stage is provided within the chamber and configured to support a substrate placed thereon. The stage includes a lower electrode. The radio frequency power supply is configured to supply a radio frequency power to excite a gas within the chamber. In this plasma processing apparatus, ions are accelerated by a potential difference between a potential of the lower electrode and a potential of the plasma, and the accelerated ions are irradiated to the substrate.
In the plasma processing apparatus, a potential difference is also generated between the chamber main body and the plasma. When the potential difference between the chamber main body and the plasma is large, energy of ions irradiated to an inner wall of the chamber main body is increased, so that particles are released from the chamber main body. The particles released from the chamber main body contaminates the substrate placed on the stage. To suppress the generation of these particles, Patent Document 1 discloses a technique using an adjustment mechanism configured to adjust a ground capacity of the chamber. The adjustment mechanism described in Patent Document 1 is configured to adjust an area ratio between a cathode and an anode facing the chamber, that is, an A/C ratio.
Patent Document 1: Japanese Patent Laid-open Publication No. 2011-228694